Computer Network Reliability Research Articles

Computer Network Reliability Optimization Calculation Based on Genetic Algorithm

How to effectively reduce the network node link cost by improving the reliability of computer network transmission system is one of the important targets of computer network reliability optimization calculation. Therefore, in the computer network reliability optimization calculation, it is necessary to integrate the computer network link medium cost, network reliability optimization mathematical model and other factors. This paper describes genetic algorithm and its implementation process, as well as the application of genetic algorithm to the network link cost and network reliability optimization calculation. In addition, it is indicated from the simulation results that genetic algorithm can effectively solve the reliability optimization calculation problem which is difficult to solve by the traditional algorithm of network, so as to speed up the calculation speed of computer network and optimize the network calculation result.

Data Transmission Reliability of a Two-source Single-sink Computer Network with a Common Arc

Data Transmission Reliability of a Two-source Single-sink Computer Network with a Common Arc

Математическое моделирование надежности компьютерных систем и сетей

Математическое моделирование надежности компьютерных систем и сетей

Evaluation of Network Reliability for Computer Networks with Multiple Sources

Evaluating the reliability of a network with multiple sources to multiple sinks is a critical issue from the perspective of quality management. Due to the unrealistic definition of paths of network models in previous literature, existing models are not appropriate for real‐world computer networks such as the Taiwan Advanced Research and Education Network (TWAREN). This paper proposes a modified stochastic‐flow network model to evaluate the network reliability of a practical computer network with multiple sources where data is transmitted through several light paths (LPs). Network reliability is defined as being the probability of delivering a specified amount of data from the sources to the sink. It is taken as a performance index to measure the service level of TWAREN. This paper studies the network reliability of the international portion of TWAREN from two sources (Taipei and Hsinchu) to one sink (New York) that goes through a submarine and land surface cable between Taiwan and the United States.

Enlightenment on Computer Network Reliability From Transportation Network Reliability

Referring to transportation network reliability problem, five new computer network reliability definitions are proposed and discussed. They are computer network connectivity reliability, computer network time reliability, computer network capacity reliability, computer network behavior reliability and computer network potential reliability. Finally strategies are suggested to enhance network reliability.

Analysis of Computer Network Reliability and Criticality: Technique and Features

The paper describes modern technologies of Computer Network Reliability. Software tool is developed to estimate of the CCN critical failure probability (construction of a criticality matrix) by results of the FME(C)A-technique. The internal information factors, such as collisions and congestion of switchboards, routers and servers, influence on a network reliability and safety (besides of hardware and software reliability and external extreme factors). The means and features of Failures Modes and Effects (Critical) Analysis (FME(C)A) for reliability and criticality analysis of corporate computer networks (CCN) are considered. The examples of FME(C)A-Technique for structured cable system (SCS) is given. We also discuss measures that can be used for criticality analysis and possible means of criticality reduction. Finally, we describe a technique and basic principles of dependable development and deployment of computer networks that are based on results of FMECA analysis and procedures of optimization choice of means for fault-tolerance ensuring.

Using minimal cuts to optimize network reliability for a stochastic computer network subject to assignment budget

In our modern society, information and data are usually transmitted through a computer network. Since the computer network's reliability has a great impact on the quality of data transmission, many organizations devote to evaluating or improving network reliability, especially for network reliability optimization. This study focuses on such a confronted problem that is to find the optimal transmission line assignment to the computer network such that network reliability is maximized subject to the budget constraint. Each transmission line owns several states due to failure, maintenance, etc., and thus the computer network associated with any transmission line assignment is called a stochastic computer network. Network reliability is the probability that the computer network can transmit the specified units of data successfully. Because the discussed problem is NP-hard, an optimization algorithm that integrates the genetic algorithm, minimal cuts and Recursive Sum of Disjoint Products is proposed. Experimental results illustrate the solution procedure and show that the proposed algorithm can be executed in a reasonable time.

Computer network reliability optimization under double-resource assignments subject to a transmission budget

This paper discusses a double-resource assignment problem to maximize network reliability for a computer network. The resources are separated into two types: one is transmission line and another is transmission facility. In particular, each resource is multistate due to full failure, partial failure, or maintenance. Such a network assigned with multistate resources is usually modeled as a stochastic-flow network. Furthermore, each resource should have a transmission cost in reality. Hence, the network reliability is the probability that a specified demand is transmitted through the network successfully subject to a transmission budget. This paper devotes to find out the optimal double-resource assignment with maximal network reliability. An optimization algorithm combining the genetic algorithm, the minimal paths, and the Recursive Sum of Disjoint Products is developed to solve the proposed problem. The experimental results show that the proposed algorithm can be executed in a reasonable time.

Network Reliability Computation by using Different Binary Decision Diagrams

In this Paper we consider three different types of variable ordering; namely optimal ordering, good ordering and bad ordering for constructing the BDD of a given network by applying three different heuristics. This classification is based on the size of the BDD, because the size of the BDD strongly depends on the ordering of variables. After that we find the reliability of the given network by these different BDD. It is observed experimentally that the results (Reliability) of applying Classical Inclusionexclusion principle are the same as obtained by applying BDD for calculating reliability of a given network in each case. However the complexity of the BDD increases in bad ordering case.

Analysis of the Component-Based Reliability in Computer Networks

Desempeno en terminos de fiabilidad de redes de computador notiva este articulo. Teoremas limite sobre la duracion extrema de cola y el tiempo de espera virtual extremo en redes de cola abierta en trafico pesado sao derivados y aplicados a un modelo de fiabilidad para redes de computador donde relacionamos el tiempo de falha de una red de computador al sistema de parametros.

Multistate stochastic network interdiction via reliability modelling and evolutionary optimization

This paper extends the current stochastic network interdiction problem (SNIP) approaches to allow for the inclusion of multistate behaviour of link flow when a given link is targeted for interdiction. Under this modelling scenario, described as the multistate SNIP, a new optimization model is described for maximizing the reliability associated with an interdiction strategy constrained to a prespecified s— t flow and a prespecified cost. An evolutionary algorithm, known as the probabilistic solution discovery algorithm, is used to obtain quasi-optimal solutions for the multistate SNIP problem. This algorithm comprises a three-step process that implements multistate network reliability computation techniques along with an evolutionary optimization routine to find interdiction strategies. The solutions to different test cases show that the optimization routine is able to identify high-quality solutions in a significantly reduced search space.

A new algorithm for calculating ventilation network reliability based on truncation error theory and network simplification

Study of reliability algorithms for large-scale and complicated ventilation networks is one of the hotspot research areas in this field both at home and abroad. At present, there is too much operand caused by combination explosion in determining ventilation network reliability; computing network reliability by using disjoint principle is one of the most efficient methods but it can not quickly determine the reliability of large-scale networks. Considering this problem, we adopt a new method of direct constructing disjoint paths, at the same time, combine the truncation error theory with network simplification technology, and propose a new algorithm for determining the reliabilities of large-scale ventilation networks. The application effect of ESR is perfect. The reliability of the ventilation network (with 189 branches) of NO.2 mine area of Jinchuan Company can be determined in 24 second by ESR algorithm provided in the paper, so the problem that can not be solved in 10 hours is solved in the paper.

Efficient Event-Driven Simulation Approaches to Analysis of Network Reliability and Performability

Exactly computing network reliability and performability measures are NP-hard problems, precluding their frequent use in design of large networks. Instead, Monte Carlo simulation has been frequently used by network designers to obtain accurate estimates. This paper focuses on simulation estimation of network reliability and performability. First, a literature survey of existing approaches is given. Then, using a heap data structure, efficient implementation of two previous approaches, dagger sampling and Markov model, are proposed. Two new techniques, geometric sampling (GS) and block sampling (BS), are developed to efficiently sample states of a network. These techniques are event-driven rather than time-driven, and are thus efficient for highly reliable networks. To gauge relative performance, computational experiments are carried out on various types of networks using the existing and the new procedures. These networks include up to 400 nodes and both binary and nonbinary structure functions are used.

EFFICIENT EVENT-DRIVEN SIMULATION APPROACHES TO ANALYSIS OF NETWORK RELIABILITY AND PERFORMABILITY

AbstractExactly computing network reliability and performability measures are NP-hard problems, precluding their frequent use in design of large networks. Instead, Monte Carlo simulation has been frequently used by network designers to obtain accurate estimates. This paper focuses on simulation estimation of network reliability and performability. First, a literature survey of existing approaches is given. Then, using a heap data structure, efficient implementation of two previous approaches, dagger sampling and Markov model, are proposed. Two new techniques, geometric sampling (GS) and block sampling (BS), are developed to efficiently sample states of a network. These techniques are event-driven rather than time-driven, and are thus efficient for highly reliable networks. To gauge relative performance, computational experiments are carried out on various types of networks using the existing and the new procedures. These networks include up to 400 nodes and both binary and nonbinary structure functions ar...

The impact of overload conditions on computer network reliability

Performance in terms of reliability of computer networks motivates this paper. A limit theorem on the extreme queue length in open queueing networks in heavy traffic is derived and then applied to a reliability model for computer networks where we relate the time of failure of a computer network to the system parameters.

Enumerating disjunctions and conjunctions of paths and cuts in reliability theory

Let G = ( V , E ) be a (directed) graph with vertex set V and edge (arc) set E. Given a set P of source–sink pairs of vertices of G, an important problem that arises in the computation of network reliability is the enumeration of minimal subsets of edges (arcs) that connect/disconnect all/at least one of the given source–sink pairs of P . For undirected graphs, we show that the enumeration problems for conjunctions of paths and disjunctions of cuts can be solved in incremental polynomial time. Furthermore, under the assumption that P consists of all pairs within a given vertex set, we also give incremental polynomial time algorithm for enumerating all minimal path disjunctions and cut conjunctions. For directed graphs, the enumeration problem for cut disjunction is known to be NP-complete. We extend this result to path conjunctions and path disjunctions, leaving open the complexity of the enumeration of cut conjunctions. Finally, we give a polynomial delay algorithm for enumerating all minimal sets of arcs connecting two given nodes s 1 and s 2 to, respectively, a given vertex t 1 , and each vertex of a given subset of vertices T 2 .

Node-pair reliability of network systems with small distances between adjacent nodes

A new method for computing the node-pair reliability of network systems modeled by random graphs with nodes arranged in sequence is presented. It is based on a recursive algorithm using the “sliding window” technique, the window being composed of several consecutive nodes. In a single step, the connectivity probabilities for all nodes included in the window are found. Subsequently, the window is moved one node forward. This process is repeated until, in the last step, the window reaches the terminal node. The connectivity probabilities found at that point are used to compute the node-pair reliability of the network system considered. The algorithm is designed especially for graphs with small distances between adjacent nodes, where the distance between two nodes is defined as the absolute value of the difference between the nodes’ numbers. The maximal distance between any two adjacent nodes is denoted by Γ( G), where G symbolizes a random graph. If Γ ( G ) = 2 then the method can be applied for directed as well as undirected graphs whose nodes and edges are subject to failure. This is important in view of the fact that many algorithms computing network reliability are designed for graphs with failure-prone edges and reliable nodes. If Γ ( G ) = 3 then the method's applicability is limited to undirected graphs with reliable nodes. The main asset of the presented algorithms is their low numerical complexity— O ( n ) , where n denotes the number of nodes.

A LOWER BOUND FOR THE NODE-PAIR RELIABILITY OF NETWORK SYSTEMS WITH SMALL DISTANCES BETWEEN ADJACENT NODES

A new method for computing a lower bound of the node-pair reliability of network systems modeled by random graphs with sequentially ordered nodes is presented. It is based on the analysis of the tree structure constructed in order to find all minimal paths connecting two distinguished nodes of the system under consideration. The algorithm is particularly efficient for graphs with small distances between adjacent nodes, where the distance between two nodes is defined as the absolute value of the difference between the nodes' numbers. The presented method can be applied if both nodes and edges are subject to failure. That is important in view of the fact that many algorithms computing network reliability are designed for graphs whose nodes are not failure-prone. Moreover, the method can be applied for directed as well as undirected graphs. The algorithm's numerical complexity depends on 2·rG - 1, where rG is the maximal distance between any two adjacent nodes. It occurs that for rG = 2 the exact value of a network system's reliability can be computed by means of a simple recursive procedure. The results of both (approximate and exact) methods are compared to demonstrate the lower bound's accuracy.

A tool for computing computer network reliability

The computation of the reliability of a computer network is one of the important tasks of evaluating its performance. The idea of minimal paths can be used to determine the network reliability. This paper presents an algorithm for finding the minimal paths of a given network in terms of its links. Then, it presents an algorithm for calculating the reliability of the network in terms of the probabilities of success of the links of its minimal paths. The algorithm is based on a relation that uses the probabilities of the unions of the minimal paths of the network to obtain the network reliability. Also, the paper describes a tool that has been built for calculating the reliability of a given network. The tool has two main phases: the minimal paths generation phase, and the reliability computation phase. The first phase accepts the links of the network and their probabilities, then implements the first proposed algorithm to determine its minimal paths. The second phase implements the second proposed algorithm to calculate the network reliability. The results of using the tool to calculate the reliability of an example network are given.

Solving advanced network reliability problems by means of cellular automata and Monte Carlo sampling

This paper extends the cellular automata-based, Monte Carlo sampling methodology for computing network reliability, previously proposed by the first author. The extension regards the development of cellular automata for the solution of the all-terminal and k-terminal connection problems and the maximum unsplittable flow problem, which can be considered as a particular, simplified case of the maximum flow distribution problem. The algorithms developed are presented in detail and verified on literature cases.